rpnstring has a small amount of command by it self. Instead it
provide interface to the C math library. The user can make own
commands by using the macro facility. In that way the calculator can
be adapted to each user according to the users needs.
Currently, this is the first version of an RPN calculator made to be easy to implement for any C# project requiring parsing of text into calculable data. Using RPN (Reverse Polish Notation) to place strings in a specific format to allow fast processing for parsing and evaluating the string.